Magnetic resonance imaging (MRI) scan
A magnetic resonance imaging (MRI) scan uses a strong magnet and radio signals to take pictures of your child’s brain.
The MRI scanner is a large, round, noisy machine with a tunnel in the centre. During the scan, your child wears a special helmet and lies on a narrow bed that slides into the MRI machine. The scan does not hurt.
The MRI scan takes about one hour. However, if your child needs a sedative for the scan (see below), please allow up to three to four hours for your hospital visit. This allows enough time for the scan and for any medicine to wear off before your child goes home.
Why does my child need an MRI scan?
The MRI takes picture of your child’s brain. Doctors are trained to look at these pictures to identify the cause of the epilepsy.
Does the scan have any risks or side effects?
If your child receives contrast, it may cause a rash or puffiness around the face and neck. However, this is very rare. The MRI team will watch your child very closely during and after the MRI to check for any reaction to the contrast and help ease any symptoms.
Tell the MRI team about any metal in your child's body
Because MRI involves a strong magnetic field, certain metal implants could injure your child. Tell the MRI team if your child has had any surgeries, procedures, implants or injuries that involved metal, such as metal rods, plates, screws, braces, clips or body piercings.
Your child will have to empty their pockets completely of everything, including coins, keys, pens, cell phones, wallets and bank cards. They will also have to take off their watch. Your child cannot wear any makeup or jewellery.
If your child does have any implants, please give the MRI team information about the type of device and the manufacturer. In some cases, your child may need an X-ray to confirm that it is safe for them to have an MRI.
Is there any preparation form MRI?
If your child is able to lie perfectly still for an hour, then no special preparation is usually needed for the scans. However, many children need medicine to help them sleep, so they will lie still for the scan. This medicine may be a type of sedation or a general anesthetic. The type of sedation or anesthetic your child needs depends on their age and medical condition.
Before having any sedation or general anesthetic, your child will need to have an empty stomach. The treatment team will tell you when your child needs to stop eating and drinking before the MRI.
What should I tell my child?
Tell your child exactly what will happen during the MRI scan. Explain what they will see, hear and feel. Remember, MRI scans do not hurt. Visit the SickKids MRI page for more information, including videos your child can watch to better understand what to expect on the day of their scan.
What to do if you need to cancel your child's appointment
If you have to cancel your child's MRI appointment or if you have any questions, please call the department as soon as possible.
If your child becomes ill before the MRI appointment
For their own safety, it is important that your child is healthy on the day of the MRI. If your child is unwell prior to the MRI appointment, please call the department as soon as possible. The MRI may need to be rebooked.
- If you are late for your child's appointment, the appointment may need to be delayed or cancelled.
Will my child need to be sedated for an MRI scan?
Some children may need a sedative (medicine to keep them calm) to help them lie still for about an hour during the scan.
What happens when my child arrives for the scan?
- An MRI team member will check if your child can lie still comfortably in the MRI machine.
- Your child will empty their clothes pockets and remove any watches, purses, jewellery and makeup. They can store these in a locker during the scan.
- Your child will change into a hospital gown and enter the MRI room.
What happens during an MRI scan?
MRI scan of the brain
The technologist will place your child’s head in a head coil, which is like a helmet. Your child will also wear earplugs or headphones to help reduce the loud knocking noise from the MRI machine.
Sometimes, health-care providers may need to give your child a special liquid called contrast to help the MRI images show more information about the brain. This liquid is put into the vein in your child’s hand or arm through an intravenous catheter.
When your child is ready, they will lie on the narrow bed that moves into the tunnel. The MRI technologist will talk to them through a speaker from outside the MRI room and remind them to stay still during the whole scan.
If your child is able to stay still without taking any medicine, they may watch a movie to pass the time.
May I stay with my child during the MRI scan?
You may stay in the MRI room with your child if:
- your child is not asleep during the study
- the technologist is sure that it is safe for you to do so, for example by asking about any metal implants or piercings
What should I expect after an MRI?
Once the scan is done, your child may get dressed and go home. If your child took any sedative (medicine to help them stay calm) during the MRI, they may leave the hospital only when they are alert and fully recovered.
When will I get the test results?
Your child's health-care provider will receive the report of the MRI scan results and discuss them with you and your child at a follow-up appointment, usually about four to six weeks after the scan.
At SickKids
If your child's health-care provider has told you that your child needs a sedative for the MRI, someone from the MRI Department will contact you with instructions on when your child needs to stop eating and drinking before their appointment.
If the MRI is booked without a sedative but you think your child needs it, please contact the MRI Department at 416-813-5774 and choose option 3.
MRI without sedation or general anesthesia
The WAGS program (Wonderful Alternatives to General Anesthesia & Sedation) provides techniques for alleviating anxiety and reducing the need for general anesthesia in paediatric diagnostic imaging, particularly in MRI. To learn more about the WAGS program at SickKids, please visit https://www.sickkids.ca/en/care-services/clinical-departments/diagnostic-interventional-radiology/wags/.